Headboard



FIG. 1 is a left front perspective view of a headboard showing my new design;

FIG. 2 is a side elevational view thereof; and,

FIG. 3 is a front elevational view thereof.

The views of the headboard not shown form no part of the claimed design. The broken lines depicting finials and posts represent environmental elements only and form no part of the claimed design. 

The ornamental design for a headboard, as shown and described. 